This study presents the first Korean records of two subtropical fish species, Pseudojuloides paradiseus and Diplogrammus xenicus, collected around Jeju-do Island, as well as one boreal fish species, Erilepis zonifer, collected in Busan (approximately 200 km away from Jeju-do Island). In this study, we discuss the implications of the species’ habitat range expansion. Previously, P. paradiseus was known as an endemic species of Japan, while D. xenicus was known to inhabit the Eastern Indian Ocean and the Pacific Ocean excluding around the equator, and E. zonifer was only known to inhabit the Pacific Ocean between eastern Japan and the western USA. Their habitat range expansions might be attributed to the expansion of the Tsushima Warm Current at the surface layer and/or the North Korean Cold Current at the bottom layer. Our findings may suggest that habitat of marine fish is being changed continuously by climate change or oceanic currents. Therefore, it needs to conduct integrated and systematic monitoring of fish fauna to response changing marine biodiversity.
